A lake in Germany has been drained in an attempt to find what's thought to be an Alligator snapping turtle (Macrochelys temminckii) after an eight-year-old boy was bitten while bathing.

The attack in the lake in Irsee left the boy's Achilles tendon severed in two places. Experts say that an Alligator snapping turtle was the most likely culprit, due to the wounds on the victim's leg.

The lake is popular with bathers during the summer holidays, but was drained at the weekend and the fish transferred to a nearby pond. Now it has been fenced off and around 50 volunteers and firefighters are wading through the mud and long grass in an attempt to find the non-native turtle, which has been nicknamed Lotti. If she buries herself in the mud, the search could come to nothing.

Meanwhile the local mayor has offered a reward for the capture of the turtle, which is thought to have been released there by its owner, a fact which has enraged locals. Warning signs have also been put up around the area.

The injured boy is said to be doing well and has reportedly asked the mayor not to harm the turtle when it's found, but re-home it at a zoo instead.

Alligator snapping turtles are the largest freshwater turtles in the world and are found primarily in southeastern U.S. Adults can have a carapace length of 75cm/30" and may weigh as much as 80kg/180 lb. They need to be handled with great care - there are reports of human fingers being bitten off by these turtles. Due to their sheer size and bulk, along with specific requirements, they don't make great pets for any but the most dedicated keepers.